Internal-combustion engine.



D. E. PRATT.

' INTERNAL COMBUSTION ENGINE. APPLIOATION FILED JULY 10, 1912.

1,080,128; Patented Dec. 2, 1913 '2 SHEETS-SHEET 1;

INV

ML w 0* v WITNESSES D. E PRATT. INTERNAL COMBUSTION ENGINE. APPLICATION FILED JULY 10, 1912.

Patented Dec. 2, 1913.

2 SHEETS-SHEET 2.

INVENTOR BY L {L 4301mm I /r c I A 1 I I I 5 WITNESSES I I DON E. PRATT, OF SAN FRANCISCO, CALIFORNIA.

rice.

, INTERNAL-COMBUSTION ENGINE.

Specification of Letters Patent.

Patented Dec. 2, 1913.

Application filed July 10, 1912. Serial No. 708,625.

To all whom it may concern:

Be it known that I, DON E. PRATT, a citizen of the United States, residing in the city and countyof San Francisco and State of California, have invented certain new and useful Improvements in Internal-Combustion Engines, of which the .following is a specification.

The hereinafter described invention relates to a new and improved internal combustion engine of the two cycle type, and'particularly to aform of engine wherein the cylinders are so arranged that one exhaust valve suffices for all.

The principal objects of the invention are to provide an engine of the above type wherein the admission of the explosive mi-xture into the cylinders is controlled by suitable valves operated by the piston rods in the respective cylinders, and'to provide an engine wherein the power generated by the charges of explosive gases is transmitted to the drive shaft by a cam ring carried thereby, and said drive shaft also carrying and controlling the operation of the exhaust- .val've for thecylin'ders. v

. A further and important object is to pro-- vide an engine in which the tappet valves are entirely dispensed with, and one which is simple and durablein construction, com-' pact in arrangement, and thoroughly'efiicient in all of its operations. v

The invention consists in a casing, a drive shaft extending upwardly therethrough, a plurality of cylinders mounted on said casing and arranged annularly relative to said. drive shaft, pistons in said cylinders, a

- valve controlled gas intake in each of said cylinders, means carried by the drive shaft and acted on by the reciprocation of the pistons for rotating said shaft, and an exhaust valve carried by said shaft and common to all of said cylinders and adapted to intermittently register with each of said cylinders. v

With the above mentioned and other objects in view, the invention consists in the construction and novel combination of parts hereinafter fully described, illustrated in the accompanying drawings,and pointed out in the claims hereto appended; it bein un derstood that various changes in the form, proportion, size and minor details of construction, within the scope of the claims the spirit or sacrificing any advantages of the invention.

To fully comprehend the invention reference should be had to 'the accompanying drawings in which-is disclosed one form of a completely constructed device for successively carrying out my invention, wherein Fi ure 1 is a longitudinal central seetiona view of a four cylinder engine of my improved type, disclosing the cylinders and supporting casing therefor, the drive shaft and the cam ring carried thereby, the pistons, the intake valves controllable thereby, and the exhaust valve common to all of the cylinders and operatable and carried by the drive shaft. Fig. 2 is a transverse sectional view taken on line 22 Fig. 1 disclosing the arrangement ofthe cylinders and the positioning of the exhaust valve relative thereto. Fig.- 3 is a transverse sectional view taken on line 33 Fig. 1 disclosing the intake valves, and the manner of mounting the cylinders on the casing. Fig. 4; is a perspective View of the drive shaft carrying the cam ring removed from the engine. Fig. 5 is a transverse sectional view taken on the line 5-5, Fig. 1.

Referring more particularly to the drawings, the reference numerall designates a suitable hollow cylindrical casing open at of the casing and which is provided inits center with an opening 6 through which is adapted to extend a shaft 7 Screw threaded at their lower ends to the upper edges of rings 8, which rest at their outer portions on the overhanging lip 3 and at their inner :portions adjacent the shaft 7 on the center of the plate 5, and mounted on the casing by the retaining rings 9 through which extend the securing bolts 10, are the engine cylinders 11, arranged an nularly relative to the shaft 7 and the upper open or exhaust ends of which are curved toward each other, as in Fig. 1, and the openings therein are adapted to be contllo led by the conical shaped exhaust valve 12 carried by the upper end of the shaft 7, the lower end of which is squared and is tical walls 2 of the casin the retaining rings 9.

received in a squared opening in the upper end 'ofthe drive shaft 13, the lower end of said shaft projecting through a suitable opening in the lower end o f the casing 1. The shaft'13 is supported in the casing by suitable anti-friction bearings 13.retained in a-runway 13 by a suitable adjustable bushing 13 ,.and a coiled expansion spring 7' encircles the shaft 7 between the adjustable nut 7 and the loose collar 7 3 surrounding the shaft, saidspring seating the exhaust valve in its seat formed at the upper open ends of the cylinders, thecollar 7 be-. ing antifrictionally mounted by ball bearings 7* positioned between the same and the overhanging flanges 7 at the inner side of Each of the cylinders 11 is provided with the usual cooling water jacket 14 and the spark plug 15, and is formed adjacent its 'lower end with an integral annular flange 16 which is spaced from the lower side walls of the cylinder, providing a by-pass 17, which communicates with the upper portion of the cylinder through the apertures 18 extending around the cylinder at the juncture of the cylinder proper and the flan e 16.

Mounte'd to reciprocate in each cy inder is a piston 19, having the usual packing rings 20' and having depending downwardly from the underside thereof a piston rod 21 which operates through a suitable opening in the late 5 and extends downwardly within the interior of the casing 1. The piston rod is bifurcated adjacent its lower end, in which bifurcation is rotatably mounted on a shaft 22, an idler roller 23 which rests on the upper edge surface of a cam ring 24:, formed integral with the drive shaft 13 and which extends upwardly around the same in spaced relation thereto, said cam ring being formed with an overhanging lip. 25 which is frictionally engaged ou its underside by a pin 26 proyecting from tiieextremelower end of the piston rod 21. Each piston rod 21 reciprocates in vertical slots 27 and 28 arranged opposite each other, the slots 27 he-; ing formed in the inner surface of the veri 1,'and the slots 28 formed in the outersurface of an annular flange 29 integral with and depending downwardly from the underside of the plate 5,

the flange being interposed between the up per ortion of the drive shaft- 13 and. the annu ar cam ring 24. v

Surrounding each piston rod 21, and ositioned between the lower edge of the ange 16 and an inwardly projecting seat 30 formed on the inner wall of the ring 8, is v the cylinder just fire be below the apertures 18 of the .y-pass 17,.

. eled surface withan annular groove 32- in which is positioned an annular fiat packing ring- 33, which is adapted to rest on the seat 30 when the plate 31 is in its lowermost position, the upper edge 34 of the plate haing of such a diameter as to rest against the underside of the flange 16 when the plate is in its uppermost posltion. i

. Suitable packing rings 35 are carried by the plate 31 and the same frictionally engage the piston rod 21 so that the plate and its associated arts, hereinafter termed an inlet valve, w1ll be operated upon the rechannel opens to the side of, the valve 12, as

at 38, and is of the same size as the open ends of the'respective cylinders; Suitable ports 39 are arranged in the overhanging lip 3 in communication with the engine cylinders and are adapted to be connected in any suitable'manner with a carbureter, not shown, for the supplying of a gaseous'mixture to the respective engine cylinders.

The operation of the engine is as follows: The respective parts being assembled as in the drawings, and as the drive shaft is manually rotated in starting the engine, the action of the cam ring 24 will reciprocate the pistons 19, the piston being on its firin stroke, as at A, will have on its upwar movement to, this position, lifted the inlet valve plate 31 which frictionally engages the piston rod, from its seat, and the suction in the base of the cylinder caused b the up ward movement of the piston wi draw'a charge of explosive mixture into the base of the cylinder behind the piston. Upon the explosion of the charge in the headof the cylinder, which was drawn. therein -on a previous suction stroke of the piston, the piston rod will be at a position B relative to the surface of the cam 24, and the impact of the explosion will force the idler roller 23 thereof against the downwardly sloping surface C of the cam, rotating theshaft and cam ring in the direction of the arrow- The piston moving downwardly on its 1 power stroke, the same will seat the intake valve plate 31 and close the aperture 18 of the by-pass 17, compress the gases within the base of the cylinder until the idler roller .23 carried by the piston rod reaches a point D on the cam ring, 24. when the piston will be. in a position, as at. E in. Fig. L, and'the channel 36of theexhaust valve 12 register with the 7 and the iston will atwhich time the Igases compressed in the ear base of the i will. rush upwardly opening, in the upper eudofmedias 18, driving the dead gases within the upper end of the cylinder outwardly through the channel 36 in the exhaust valve 12. The exhaust valve remains open but for a short period, only while the piston in the cylinder just fired is traveling between the points E and F on the cam, after which time the upwardly inclined surface G of the cam will be presented to the idler roller and the piston elevated to its firing stroke, and the above operations will again be performed as described. The engine cylinders are so positioned and the cam ring 24: is so formed,

combination with a stationary casing, a-

drive shaft rotatably mounted therein, cylinders mounted on said casing and arranged circumferentially of said drive shaft, a piston slidably mounted in each of said cylinders, each of said cylinders provided at its lower end with an inlet port for the admission into said cylinders of an explosive charge and at its upper end with a normally closed exhaust port for the escape of the exploded gases from within said cylinders, a valve carried by each of said pistons and operated by'the movement thereof for controlling said inlet ports, a cam carried by said drive shaft and cooperating with said pistons for transmitting power therefrom to said drive shaft, meanswit-hin each cylinder for firing the explosive charge contained therein, and an exhaust valve common to all of: said cylinders and operated by the rotation of-said drive shaft for intermittentlyopening the exhaust ports of the cylinders to the atmosphere, for permitting the escape of the exploded gases contained within the cylinders.

2. In an internal combustion engine, the combination with a casing, astationary drive shaft rotatably mounted therein, cylinders mounted on said casing, and arranged cir cumferentially of said drive shaft, a .piston slidably mounted in each of said cylinders,

each of said cylinders provided at its lower end with an inlet port for the admission into said cylinders of an-explosive charge and by each of said pistons and controlled by the movement thereof for controlling said inlet port adapted upon the rotation of said valve to intermittently register with the exhaust ports of the cylinders for permitting the escape tothe atmosphere of the exploded gases fromrw'ithin the cylinders.

' 3. In an internal combustion engine, the combination with a stationary casing, a drive shaft rotatably mounted therein, cylinders mounted on said casing and arranged circumferentially of said drive shaft, a piston slidably mounted in each of said cylinders, a piston rod depending therefrom and extending within said casing, each of said cylinders provided at its lower end withan inlet port for the admission into said cylinders of an explosive charge and at its upper end with a normally closed exhaust port for the escape of the exploded gases from within said cylinders, aca-mcarried by'said drive shaft and cooperating with said piston rods for transmitting power therefrom to said drive shaft, a valve associated with each of vsaid piston rods and operatable by the movement thereof for controlling the inlet port and admission into the cylinders of an explosive charge, means within each cylinder for firing the explosive charge contained therein, a rotary conical shaped exhaust valve carried by the end of said shaft and positioned in a conical opening arranged centrally between the upper ends of said cylinders and-operated by the rotation of said drive shaft for intermittently opening the exhaust ports of the cylin' ders to the atmosphere'for permitting the escape of the exploded gases contained within the cylinders and means under tension and associated with said shaft for maintaining said valve seated.

4. In an internal combustion engine, the combination with a statienarily mounted casing, a drive shaft rotatably mounted therein, a driven'shaft detachably secured to and operated by said drive shaft, cylinders mounted on said casing and arranged circumferentially l of said driven shaft, 'a piston slidably mounted in each of said cylinders, a piston rod depending therefrom and extending within said casing, each of said cylinders provided adjacent its lower end with an inlet port for the admission into said cylinders of an explosive charge and at its upper end a normally closed exhaust port for the escape of the exploded gases from within said cylinders, a cam carried by said drive shaft and cooperating with said piston rods for transmitting power there from to said drive shaft, a compression 5 chamber surrounding-thelower end of each 4 cylinder, a valve associated with each of said pistons and operatable by the movement thereof for controlling the admission into the cylinders and compression chambers of--an explosive charge, means within each cylinder for firing the explosive charge containedtherein, a rotary conical shaped exhaust valve carried by the end of said driven shaft, said valve provided with an angularly disposed exhaust port communicating at i one end with the atmosphere and positioned in a conical opening arranged centrally of the upper endsof said cylinders and adapted upon the rotation of said valve to intermittently register with the exhaust ports of the cylinders for permitting the escape of the dead gases therefrom and spring pressed means interposed between the lower end of said driven shaft and said casing for maintaining said valve seated.

5. In an internal combustion engine, the

combination with a stationarily mounted casing, a drive shaft rotatably mounted therein, a driven shaftoperated by said drive shaft, a cylinder mounted on said casing, a piston slidably mounted in said cylinder, said cylinder provided at its lower end with a valvecontrolled inlet port for the admission'tliereinto of an'explcs'ive charge and I at its upperend with a normally closed exhaust port for the escape of the exploded gases therefrom, a cam carried by said drive r-j shaft and cooperating with said piston for transmitting power therefrom to saiddrive shaft, means for firing the explosive charge within said cylinder, a conical-valve seat associated with the upper end of said cylinder,

a conical shaped rotary exhaust valve positioned in said valve seat and carried by the end of said driven shaft said valve being operated by the'rotation ofv said drive shaft for intermittently opening the exhaust port of c said cylinder for permitting the escape to the atmosphere of the exploded gases contained therein, and spring pressed m'eans associated with the lower end of said driven shaft for retaining said valve in its seat.

6. In an internal combustion engine, the combination with a stationarily mounted casing, a drive shaft rotatably mounted ing tl ierefrom and extending within said.

casingand connected to said drive shaft, fiiezl ichambers fin said casing adjacent the lower end of each of said cylinders, a connection betwee'n'eajcli ofsaid fuel chambers and a sourceofjfuel supply, a communication between'eaehofsaidfuel chambers and said cylinderslavalve associated with each of said piston rods and operatable by the movement thereof for contrdlling the communication between said fuel chambers and said cylinders, said cylinders provided at their upper end with a normally closed exhaustport for'theescape of the exploded gases from within the cylinders, means for firing the explosive charge within the cylin- 7. In an internal combustion engine, the

combination with a stationarily mounted therein, a cylinder mounted onsaid casing, a piston slidably mounted in said cylinder, a piston rod depending therefrom and exders, and an exhaust-valve common to all of.

casing, adrive shaft rotatably mounted tending withinsaid casing, a cam carried by g 1 said drive shaft and cooperating with said piston rod for transmitting motion therefrom tosaid' drive shaft, said casing being,

provided with a fuel chamber, a communication hetweenithe fuel chamber anda source of'fuel 1pply,' a communication between the fuel chiimber and the lower endof said cylcommunicating at'its upper and lower ends with the interior of said cylinder, said piston on its downward movement compressing the gases into said chamber and controlling-- the upper communic tion between said compression chamber ad cylinder, means-for firing the charge within the cylinder and a valve controlled exhaust port for the escape of the exploded gases 7 therefrom.

In testimony whereof I have signed my name to this specification in the presence of two subscribing witnesses.

i DONE. PRATT.

Witnesses:

HARRY A. Town, D. B. RrcHAnns.

95 inder, a valve associated with said piston.

. 1 d the interior of said 

